1. Field of the Invention
The present invention relates to high frequency modules through which high frequency signals complying with a plurality of communication systems or band classes pass and high frequency components constructed by mounting high frequency modules on module mount boards.
2. Description of the Related Art
In recent years, cellular phones with specifications complying with a plurality of communication systems or band classes (see Japanese Unexamined Patent Application Publication No. 2003-152588, for example) are becoming more common. Thus, high frequency modules installed in these cellular phones are configured to include a switching device and a plurality of filter circuits. The switching device is configured to include a plurality of connection switch ports that switch between connection destinations of antenna. The plurality of filter circuits is connected to the respective connection switch ports. Each filter circuit is configured to pick up a frequency that corresponds to one of the plurality of communication systems or band classes.
The specifications of communication systems or band classes or the like used in cellular phones generally differ depending on the area or provider of communication service. Further, a conventional high frequency module is configured to comply with one specification of cellular phone, and not comply with a plurality of specifications of cellular phone.
Thus, a supply side of high frequency modules such as module makers and the like is required to develop, design, and manufacture high frequency modules that comply with each cellular phone specification. This prevents development of a common high frequency module for use in a plurality of specifications of cellular phone, leading to unchanging higher supply costs and longer supply periods.
Further, a demand side of high frequency modules such as cellular phone makers and the like is required to keep track of high frequency modules for each specification of cellular phone. This complicates the management of components as the number of components to be managed increases.
In view of the above, it may be conceivable to make the high frequency module compatible with the cellular phone with a plurality of specifications by increasing the number of the connection switch ports in the switching device or the filter circuits to include additional compatible communication systems or band classes. However, in such cases, it also means that the number of the connection switch ports of a switching device is to be increased in response to the number of the communication systems or band classes to add. In other words, the switching device of the high frequency module will include unused ports. This leads to a higher cost for the switching device and makes it more difficult to justify a cost-cutting effect from using the common high frequency module.